Generally students will get financial aid and scholarships that cover much of the cost of tuition, especially if they’re from a lower income family. I’m guessing that, as an international student from a wealthier family, your son didn’t quality for much aid. Tuition is also generally lower for residents of the state, which he also wouldn’t qualify as.
Even with all that it’s still incredibly expensive and lots of people end up having to take out large loans or work jobs while in college to cover the cost.
Maybe puzzles? I’m not sure whether that’s what you’re going for, but it could fit.